Apparatus for heating



Nov. 28, 1933. H. c. FRENTZEL, JR

APPARATUS FOR HEATING Filed June 29, 1932 Patented Nov. 28, 1933 UNITED STATES PATENT QFFICE APPARATUS FOR HEATING Application June 29, 1932. Serial No. 619,885 7 claims. (o1. 122-182) The present invention relates in general to improvements in the art of transferring heat, and relates more specifically to an improved apparatus for heating one iiuid With the aid of another.

Generally stated, an object of the invention is to provide an improved apparatus for transferring heat from one iluid to another.

Some of the more speciiic objects of the pres- 110 ent invention are as follows:

To provide an improved structure yfor transferring heat from hot gases to a heat absorbing medium such as Water or air, with minimum loss of available heat.

To provide a simple, compact and highly eilicient heater for transferring heat from hot gases to a flowing heat absorbing medium such as water or air.

To provide a new and useful heating device for household or other service, which may be utilized either for space heating with the aid of steam, hot water or hot air, or for the purpose of merely producing hot liuid for divers usesk such as Washing, bathing, and so forth.

To provide a compact heating unit which may be readily constructed and operated, and all portions of which are conveniently accessible for inspection, cleaning and repairs.

To provide heating apparatus which is durable in structure, and which operates upon theoretical principles assuring maximum efficiency and economy.

To provide a nexible heating unit especially operable in conjunction With an oil or gas burner,

and which presents an attractive appearance making it an asset to any building or home.

To provide a simple hot Water heater vespecially adapted for industrial and domestic uses, which may be manufactured and operated at minimum cost.

To provide an improved boiler wherein the heat transfer surfaces are positioned so as to insure most eiiicient transfer of heat units While retaining maximum durability of the structure, and

in which the heating gases are utilized to the utmost extent Without interfering with the draft.

To provide a self-cleaning boiler structure wherein the heat transfer surfaces are constantly scoured by the action of the hot gases, and in which removed sediment drops free of the heat transfer surfaces.

To provide a relatively small and compact furnace or boiler having relatively large capacity as compared to similar devices now on the market.

These and other objects and advantages will be apparent from the following detailed description.

A clear conception or" one embodiment of the invention and of the mode of constructing and of operating a hot Water heater built in accordance with the improvement, may be had by referring to the drawing accompanying and forming a part of this specification in which like reference characters designate the same or similar parts in the various views:

Fig. l is a central vertical section through a hot Water heater or boiler which is fired with `the aid of an oil burner;

Fig. 2 is a transverse horizontal section through the heater of Fig. l, taken on the line 2--2A of Fig. 1 and looking down; and

Fig. 3 is a transverse horizontal section through the same heater, taken on the irregular line 3-3 of Fig. l and looking down.

The improved heating unit shown in the draw-A ing by Way oiillustration, comprises in general an outer cylindrical casing 5 and an inner circular casing 6 cooperating with the outer casing to form a central combustion chamber 7 surrounded by an annular rluid confining jacket or chamber 8. The outer casing 5 may be formed of heavy steel plate, and is completely surrounded by a layer 9 of heat insulating material which is-in turn surrounded by an outer covering l0 formed of relatively thin plate painted or enameled any desired color. The lower cylindrical portion of the inner casing 6 may also be formed of heavy plate metal and is lined at the sides and bottom with refractory material ll such as :lire brick. The upper dome portion 12 of the inner casing 6 is likewise formed of heavy material and is frustro-conical in shape, converging toward the top and being directly exposed to the chamber 8. The casings 5, 6 are connected by a conduit 13 located near the lower ends thereof, and by an inspection duct le located above the conduit. The conduit 13 is provided with a closure l5 having an olset opening adapted for the reception of the nozzle 16 of an oil burner 17 or the like, so that the fuel and air delivered by the nozzle into the combustion chamber 8 enters tangentially and thereby produces a whirling vortex of the burning mixture and of the resultant gases of combustion as they rise upwardly through the tapered casing portion l2. The conduit 13 is of sufcient Width to permit disposition of the nozzle 16 therein tangentially of the combustion chamber 7, and the portion of the conduit interior which is not occupied by the nozzle is normally lil() Cin lled with refractory material. The inspection and clean-out duct le may be provided with a door 13 having a peep-hole 19 covered with heat resistant transparent material which will permit observation of the chamber 'l at all times.

The upper constricted delivery opening of the dome portion 12 communicates with a flow reversing chamber formed by a downwardly tapered upper tube sheet 21, an auxiliary cylindrical in' er casing 22, and a removable top cover 23, the two former of which are likewise exposed directly to the chamber 3. The lower inner edge of the tube sheet 21 secured as by welding, directly to the upper edge of the dome portion 12 at the constricted central opening, and the upper outer edge of the tube sheet 21 is attached di ectly to the lower end of the casing 22. The upper end of the auxiliary casing 22 is connected to the upper end of the outer casing 5 by an annular plate 2e, and the sheet 2l, casing 22 and plate 24 are again preferably formed of relatively heavy sheet material. be formed of a slab of heat resistant insulating material confined within an outer metal retainer and the cover 23 is detachably secured to the upper end of the heater by means of bolts 25 coacting with annular inspection. cover 27 which is secured to the heater covering 13. Upon removal of the top cover free access is had to all portions of the chamber 20, without necessity of removing the cover 27.

The lower ends of the casings 5, 5 are ccnnected by a lower tube sheet 23 formed heavy steel plate, which rests directly upon a base 29 having a gas collecting chazfnber 3 therein. The upper and lower tube sheets 21, 23 are interconnected by a series of curved tubes 31 and afford open passages connecting the upper chamber 20 with the lower chamber 3c, of sumcient total cross-sectional area to prevent undesirable retardation to the flow of gases therethrough. The tubes 31 extend through the length of the jacket chamber 3, and this chambe is provided with lower cold duid inlets 32 and with upper hot fluid outlets 33. The heater base 29 may be formed as a casting which may be mounted upon a suitable foundation and the rear of the chamber located within the base communicates directly with a stack or other draft producing device. A clean-out door 35 is provided on the base 29 near the stacl; 35, and permits free access to all portions of the lower chamber 30.

The major portion of the improved heater may be formed of sheet metal plates welded together, and the exterior of the heater may be painted, enameled or otherwise decorated in any desired manner. The entire exterior of the chamber 8 should be insulated against heat losses, and the combustion chamber 7 may obviously be fired either with gas, oil, or solid fuels.

During normal operation of the improved heater, heat transferring medium such as water be admitted to one of the inlets 32, and heating fluid may be delivered from one or both of the outlets 33, depending upon the specific use to which the apparatus is being put. The fuel and air are admitted to the combustion chamber 7 through the conduit 13 and are ignited therein. The gases of combustion are caused to whirl by virtue of the tangential disposition of the nozzle 15 and rise upwardly through the interior of the dome portion 12 as a whirling vortex of highly heated gas. By virtue Vof the tapered formation of the dome portion 12,

The renovable top cover 23 may.

considerable heat is transferred to the medium within the chamber 8 during the ascent of the vortex. As the heated gases enter the chamber 20 they strike the top cover 23 and the now thereof is reversed. The heated gases then pass downwardly through the tubes 31 and further heat the medium within the chamber 8, being eventually discharged into the lower chamber 30 in the base 29 where the individual streams of gas commingle. By the time the gases reach the chamber 30, by far the greater proportion of their heat has been transferred to the heating medium within the chamber 8, and the spent gases are subsequently delivered from the chamber Si) through the stack 35.

It will be apparent that the construction of the dome portion 12 and of the tubes 31 is not only such that the heat is transferred to the heating medium within the chamber 30 with maximum efficiency, but that the surfaces which are exposed directly to the gases are automaticallyscoured and maintained free from accumulation of coatings which would tend to retard effective heat transference. The heating medium within the chamber 8 constantly circulates up-'j 100 wai-diy through this chamber and the hottest portion of this medium is obviously exposed to the gases or" combustion while these gases are in their most highly heated condition. While two inlets 32 and outlets 33 have been shown, the5 105 number of these inlets and outlets obviously be varied, and some of them may be blanked ofi' during normal use of the heater. The inspection opening 19 furthermore permits observation of the combustion conditions within theglo chamber 7 so that the burner 17 may be readily adjusted to produce most effective combustion. nstead of a stack 35, any other form of Asuction producing apparatus may be utilized, and the oil burner 17, as previously indicated, may alsjlli be replaced by other forms of fuel injection apparatus.

It should also be noted that kall portions of the improved heater are readily accessible for inspection and cleaning. The doors 15, 18 permiljlO lateral entry into the chamber '7, while the top cover 23 permits free entry to the chamber 20 for the purpose of cleaning the tube sheet 21, casing portion 12 and tubes 31. The door 36 associated with the base 29 permits access to the; 125 chamber 30 for the removal of sediment deposited therein from the tubes 3l and otherwise, thus permitting the apparatus to be maintained in most effective condition at all times.

From the foregoing description it will be ap-`;;30 parent that the present invention provides a simple, compact and highly efficient heating unit which may becaused to present an extremely neat appearance. The unit may be manufactured at moderate cost and due to its high efliciency mailbe operated with minimum fuel consumption, and this assertion has been proven by the successful commercial operation of units builtin laccordance with this invention. The number of tubes 31' and the size thereof may obviously be varied .140 to suit different heating conditions, and the invention is applicable to heaters utilizing either water or air as well as otherl fluids, such as a heating medium. In this improved heating unit, the

-lieat distribution is effectively balanced, by vir-2345 tue of the fact that the hot gases are admitted to the extreme upper ends of the tubes 31 whereas the spent gases are delivered from the extreme lower ends thereof. This method of circulation produces uniform velocity of flow through all ofl the tubes 31, and insures maximum eiiiciency. The lining 11 of the combustion chamber 7 functions as a heat insulator and accumulator, and permits the combustion chamber temperature to be maintained suiiciently high to insure complete combustion of the fuel. Any heat conducted through this lining is delivered directly to the heating medium within the chamber 8, thereby avoiding heat losses.

It should be understood that it is not desired to limit the invention to the exact details of construction of the apparatus herein shown and described, or various modifications within the scope o1 the claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. In a heater, a main cylindrical casing, a central cylindrical casing disposed within and spaced from said main casing, a tapered casing attached to the upper end or" said central cylindrical casing, an upper reversely tapered tube sheet attached to the upper end of said tapered casing, a lower tube sheet connectingsaid cylindrical casings, and a series of tubes connecting said tube sheets and extending through the space between said cylindrical casings.

2. In a heater, a main cylindrical casing, a central cylindrical casing disposed within and spaced from said niain casing, a tapered casing attached to the upper end of said central cylindrical casing, an upper reversely tapered tube sheet attached to the upper end of said tapered casing. a lower tube sheet connectiing;V said cylindrical casings, a series or tubes connecting said tube sheets and extending outwardly and downwardly through the space between said cylindrical casings, and means for constantly removing gas from the lower ends of said tubes.

3. In a heater, a cylindrical outer casing, a lower cylindrical inner casing disposed within and spaced from said outer casing, said lower casing having a refractory lining, a tapered dome portion secured to the Lipper end of said lower cylindrical casing, a tapered tube sheet connected to the upper end of said dome portion and eX- tending outwardly therefrom, an upper inner cylindrical casing connecting the outer edge of said upper tube sheet with said outer casing, a lower tube sheet connecting said outer casing with said lower cylindrical casing, a series of tubes connecting said tube sheets and extending through the space between said outer and lower cylindrical casings, means for injecting hot gases into said lower cylindrical casing, and means for removing gases from the lower ends of said tubes.

4. In a heater, a main casing, a central circular casing disposed within and spaced from said main casing, a tapered circular casing extending upwardly rrom said central casing, an upper reversely tapered tube sheet extending upwardly from the upper constricted end of said tapered casing, a lower tube sheet between said main and central casings below said upper sheet, and a series of tubes connecting said tube sheets and extending through the space between said main and central casings.

5. In a heater, an outer casing, an inner annular casing disposed within and spaced from said outer casing, means for effecting injection of fuel tangentially into the lower portion of said annular casing, an annular tapered casing extending upwardly frorn the upper end kof said annular casing, a reversely tapered tube sheet extending upwardly from the upper constricted end of said tapered casing, a lower tube sheet between said outer and inner casings below said upper sheet, and a series or" tubes connecting said tube sheets and extending through the space between said outer and inner casings.

6. In a heater, an outer casing, an inner casing disposed within and spaced from the lower portion of said outer casing,` means for effecting injection of fuel tangentially into the lower portion of said inner casing, a tapered casing converging upwardly frorn the top or said inner casing and spaced inwardly from the upper portion of said outer casing, a reversely tapered upper tube sheet extending upwardly and outwardly away from the constricted top of said tapered casing, and a series of tubes extending downwardly and outwardly from said tube sheet through the space between said outer casing and said tapered and inner casings.

7. In a heater, an outer casing, an innercasing disposed within and spaced from the lower portion or" said outer casing, a tapered casing converging upwardly from the topof said inner casing and spaced inwardly from the upper portion of said outer casing, a reversely tapered upper tube'sheet extending upwardly and outwardly away from the constrictedtop of said tapered casing, and a series of tubes extending downwardly and outwardly from said tube sheet through the space between said vouter casing and said tapered and inner casings.

HERMAN C. FRENTZEL, JR. 

